Extremly small unwanted distances

[janwoerheide]

Dear Sir or Madam,

I recently started working with Fusion 360 and encountered a rather strange problem.

In some places in my model, there are unwanted and extremely small distances that should not occur. Most of them, I cannot get rid of, whatever I try! In photo 1, you can see the distances. But they are so small, that they are not even recognized when I measure from a Position more far away. See photos 2 and 3.

1

23

Is this a bug or am I doing something wrong? 

I also attached the file.

Thank you in advance!
Sincerely,

Jan Wörheide

[paul.clauss · Accepted solution]

Hi @janwoerheide

Thanks for posting! I think this is a little bit of a combination of Fusion 360s ASM tolerances and lost references in the model. The design timeline does show a number of warnings around projected geometry, which could have triggered this behavior initially.

Part of this has to do with the tolerance that Fusion can compute dimensions to. This is discussed in this article - in short, all computations create some "noise" and Fusion will show some inaccuracies at precisions higher than six decimal points (or very near to it).

I did, however, notice that two faces that should be continuous have a split between them. This could be due to the lost references or an imprecise move command - it is hard to say which. I was able to clean up the model a bit using the "re-anchor" command as shown in the screencast below.

I hope this helps. Please let me know if you have any questions.

[janwoerheide]

Thank you very much for the fast reply and the video! I did not know the re-anchor command, very useful! (I'm pretty new to Fusion 360)

Your post and video cleared everything up for me. The ultra small distance isn't a problem at all, I just was not sure if it was a bug or my fault.

Just one more question, will there be a "solution" in the future at some point? Because it can cause trouble when you want to connect a joint, because any distance above zero will cause (and had caused, in my model) a not working system if you got more joints. 

Thanks again, honestly I did not expect such a detailed reply in such a short time!

Have a good week!